Citizens United vs. the FEC was a 2009/2010 US Supreme Court case that did precisely what you are suggesting. They addressed it, and in a 5-4 decision....the conservative justices on the court immitated the "activists" they so often demonize by creating a new interpretation of the first amendment that says, in essence, that unlimited amounts of money donated from nefarious sources to support or defeat certain political candidates in elections....is, now, considered "speech."